Phallusia nigra

Hirose, E. (1999) Pigmentation and add storage in the tunic protective functions of the tunic cells in the tropical asddian Phallusia nigra. Invertebr. Biol., 118,414-422. 

Table 28.14 Main complexes of vanadium in Ascidia ceratodes and Phallusia nigra...

Frank, P., Robinson, W.E., Kustin, K., and Hodgson, K.O. (2001) Unprecedented forms of vanadium observed within the blood cells of Phallusia nigra K-edge X-ray absorption spectroscopy. J. Inorg. Biochem.. 86, 635-648. 

Certain vertebrates have an astonishing ability to accumulate vanadium in their blood. For example, the ascidian seaworm Phallusia mammilata has a blood concentration of V up to 1900 ppm, which represents more than a millionfold concentration with respect to the sea-water in which it lives. The related organism Ascidia nigra has an even more spectacular accumulation with concentrations up to 1.45% V (i.e. 14 500 ppm) in its blood cells, which also contain considerable concentrations of sulfuric acid (pH 0). One possibility that has been mooted is that the ascidia accumulates vanadate and polyvanadate ions in mistake for phosphate and polyphosphates (p. 528). 

The chemistry of the family Ascidiidae is essentially a matter of the presence and role of vanadium in species of the genus Ascidia. The identification of sulfated alkanes and terpenes in Ascidia mentula and peroxysterols in Ascidia nigra, Ascidiella aspersa and Phallusia mammil-lata has already been mentioned (see Chapter 26 and above in this chapter). An unusual peroxy derivative. 

---